Stem cell transplant may be beneficial in patients with treatment-refractory relapsing-remitting MS.

Researchers recently published the 5-year results of the HALT-MS study, reporting that 69% of patients who received high-dose immunosuppressive therapy after autologous hematopoietic stem cell transplant (HDIT/HCT) experienced no disability progression, relapse, or new brain lesions associated with relapsing-remitting multiple sclerosis (RRMS).1

“These extended findings suggest that one-time treatment with HDIT/HCT may be substantially more effective than long-term treatment with the best available medications for people with a certain type of MS,” said National Institute of Allergy and Infectious Diseases (NIAID) director Anthony S. Fauci, MD, in an NIH news release.2 “These encouraging results support the development of a large randomized trial to directly compare HDIT/HCT to standard of care for this often-debilitating disease.”

The trial included 24 participants with RRMS who underwent HDIT/HCT. The primary end point was “event-free survival,” which the investigators defined as “survival without death or disease activity from any one of: disability progression, relapse, or new lesions on MRI.” After a median follow-up of 62 months, the rate of event-free survival was 69.2%, with progression-free survival, clinical relapse-free survival, and MRI activity-free survival at 91.3%, 86.9%, and 86.3%, respectively. Improvements of -0.5 in Expanded Disability Status Scale score were also noted in patients who survived and completed the study.

Adverse events included cytopenias and infections related to the toxic effects of the high-dose chemotherapy used for immunosuppression. Of note, no acute neurologic adverse effects occurred. Three patients who experienced disease progression over the course of follow-up died, although the deaths were not attributed to treatment.

The findings, if confirmed in larger studies, will be significant in patients with active RRMS who do not respond well to existing disease-modifying drugs.